The present invention relates to a device for damping pivotal movements of a wheel-supporting pendular arm of a motor vehicle. The invention relates especially to such a device for both position and speed-dependent damping of pivotal movements of wheel-supporting pendular arms of a tracked motor vehicle.
DE-A-1 961 008 has previously disclosed a springing and damping device for damping pivotal movements of a wheel-supporting pendular arm of a tracked vehicle, the device comprising a housing with a cavity for rotatable support of a swing axle of the pendular arm; a plate pack arranged in the housing and comprising a number of coaxially adjoining, annular disk plates, which are alternately torsionally fixed but axially moveable in the housing or on the swing axle; a first annular pressure disk torsionally fixed but axially moveable on the swing axle of the pendular arm; a second annular pressure plate, torsionally fixed but axially moveable in the housing, the two pressure plates having opposing sides with members designed, on rotation of the first pressure plate, to produce an axial movement of the pressure plates in relation to one another; and compression spring unit, designed to exert a compressive force on the pressure plates and the disk plates. Springing movements of the pendular arm are permitted by a torsion bar, to which the pendular arm is connected, whilst a position-dependent damping of compressive springing movements of the pendular arm is achieved in that friction disk plates are pressed against one another and against a brake disk in the housing through the action of the compression spring unit, when the pressure disks are separated from one another by means of interacting wedge elements in compressive springing of the pendular arm.
In extreme off-road driving conditions of a tracked vehicle with such a springing and damping system, bottoming easily occurs unless the system is of very rigid design, which has an adverse affect on comfort in ordinary road driving conditions.
An object of the invention is to produce an improved device for damping pivotal movements of the wheel-supporting pendular arms of a tracked vehicle, which device will permit both position-dependent and speed-dependent damping of the pendular arms in the case of compressive springing and position-dependent damping in the case of extension springing in order to produce a good, comfortable springing and damping function both in ordinary driving of the vehicle on roads and in extreme off-road driving conditions.
With this object in view, the aforementioned device according to the invention is characterized in that it comprises an axially moveable piston, arranged between the compression spring unit and the pressure plates, and a restrictor element, which allows a hydraulic pressure medium to flow from one side of the piston to the other. A damping device is thereby obtained, which due to the supporting of the piston between the compression spring unit and the pressure disks is capable of functioning as a hydromechanical damper, which is capable of braking rapid compression springing movements of the pendular arm and preventing bottoming.
Further special features of the damping device according to the invention are specified in the following dependent claims.
The invention is described in more detail below with reference to drawings attached.